Matt Lohry

Looks like Anonymous is going crazy and arguing with him(her)self...

The arson reports first surfaced on the American Society of Civil Engineers website, which is otherwise perfectly legitimate, so to me there was all the reason in the world to take the story as legitimate. If it were Wikipedia, Pinterest, Facebook, or other similar social media outlets, then there would be more reason for scrutiny, but given the circumstances I cannot fault Amanda for taking the story as truth. At least we all know what’s going on now!

Hi Amanda, I’m certainly not trying to create schism on this website, and to the bridge’s credit it is a truss, but the positives end there....this is a common, bland, Wal-mart inspired, mail-order bridge that is found in many, many parks across the country. They have used this bridge type in at least one location in my state of Wisconsin to replace an actual historic (and beautiful) truss bridge that was not in the way of anything and was in great shape, which is senseless and destructive. In this case, thankfully, they didn’t replace an historic bridge, but they could have used an actual historic bridge here instead of this, which would have enhanced this area and preserved a piece of history. With New York City’s commendable preservation record, I’m actually surprised that they went this route here.

I think they gave it that name because it’s so painfully ugly that when you walk across it you’d swear you were walking into hell.

The 2015 bridge is built over Bronx Kill and is built through the arched supports for this bridge:

http://bridgehunter.com/ny/new-york/amtrak---bronx-kill/

The Othmar Amman bridge is the blue lift footbridge that Luke referenced before.

The bridge in the photo is built over Little Hell Gate and was built in 2003. If you go to google earth to this bridge and use the clock function, you will see that the bridge appears in the August 2003 frame.

Folks, I have an explanation—the 2015 bridge is built over Bronx Kill right underneath the existing Bronx Kill Amtrak Bridge, on the northeast side of Randall’s Island. It’s not visible from the satellite view, but it’s there. The bridge in the photo was built in Summer 2003 (the caption with Photo #3 came from Pinterest and is incorrect).

I’ll attempt to add a bit of engineering sense to this connection type, as they were done like this for a couple of reasons: as Nathan mentions, one primary advantage of pinned joints is that they theoretically eliminate a force that is referred to as a “moment”. A moment is a rotating force that exists in true rigid connections, such as in the case of a street light pole bolted to a concrete foundation, where there are 3 different forces acting on the base of the pole—you have an axial (up and down) force, a shear (sideways), and you have the rotating bending moment. Changing to a pinned connection eliminates the moment, leaving only the axial and shear forces to calculate. This greatly simplifies calcs when doing them manually. The other reason for this type of connection is that the beams at the time were not long enough to allow the distances between spans that they needed, so simply placing each beam between supports wasn’t feasible. This was the solution. It was done to allow the supports to hold up the adjoining beams and to suspend intermediate beams with pins, thereby allowing greater distances between supports. Cantilever truss bridges function very much the same way. Stringer bridges these days use beams that can span much longer distances, so this connection type is not commonly used anymore. And to answer Don’s question, yes, these are effective expansion joints as well. If you remove the pinned plate, you would find a “stair-step” joint underneath that allows independent side-to-side movement for expansion. Hope this helps to clear things up a bit.

The connections are all riveted, which is making me question that date...I could be wrong, but it seems to me that rigid connections did not come into use until after the turn of the 20th century.

Let us also keep in mind that this track is brand new, which eliminates the infrastructure spending reasoning right there...this track was placed in the exact same spot that the old track was...they pulled up the rails and ties and laid new ones in the same exact place; they did not change the alignment at all. The curve that the derailment occurred on was just fine...for freight trains traveling at 30 mph or less, not for a train moving at 80 mph—not to speak of the fact that this curve has a posted 30-mph speed limit. Basically, the operator of the train ignored the speed limit, and that’s what caused the wreck.

They’re all high-fiving themselves because they “preserved it digitally”!! EPIC FAIL

Robert,

Very well put; I couldn’t agree more. People from every political affiliation are contributors to this site, but despite those differences, we all have the same thing in common—we love and treasure our historic bridges, and that will never change. Political comments create division, no matter what side you’re on. As I’ve said before, whining about political stuff is what Facebook is for (which I ignore completely, so it doesn’t affect me!); Bridgehunter is not the place for it.

Given its treatment of its historic bridges, TDOT should change their name to TennDOT, since it sounds just like PennDOT!

Luke,

Good golly, that is nasty--no point in wasting fuel to drive the 8 miles from my house to see it! Thanks for the head's up. EPIC FAIL!

I just saw a notice in our county newspaper that the dedication for the "New Walking Bridge" in Allenton is set for Friday, Nov. 3, 2017, a pic of the old bridge was the only pic there is...I am very fearful of what I'm going to find here, but I have to go check. I'll update with whatever nasty news I come up with! :'>(

I just discovered this bridge on Google Earth--it's on a private driveway, and as such, has no NBI data associated with it. I don't know how long it has been since the bridge serviced a public road, but the bridge appears to be built in the early 1900's or 1910's.